CN108162964B

CN108162964B - Vehicle control device

Info

Publication number: CN108162964B
Application number: CN201711192022.2A
Authority: CN
Inventors: 达城宏真; 熊崎健太
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2016-11-25
Filing date: 2017-11-24
Publication date: 2020-11-20
Anticipated expiration: 2037-11-24
Also published as: DE102017221007A1; US20180148063A1; US10239536B2; JP6455499B2; CN108162964A; JP2018083602A

Abstract

The invention provides a vehicle control device, which aims to harmonize the driving performance and the fuel economy on a slope road in the vehicle control device with a running mode in which driving force control and gear shift control are performed without acceleration and deceleration operations. The vehicle control device includes an up-down-slope AI control unit that controls the automatic transmission so as to maintain a higher engine speed during traveling on a sloping road than during traveling on a flat road, and can achieve excellent drivability during traveling on a sloping road, while limiting the extent of increase in the engine speed during the second travel mode as compared to the first travel mode, thereby improving fuel economy. In the second running mode, since the driver does not perform the acceleration/deceleration operation, the driver's request for drivability is limited, and there is a low possibility that the driver will be given an uncomfortable feeling even if drivability is slightly deteriorated by limiting the increase width of the engine speed.

Description

Vehicle control device

Technical Field

The present invention relates to an improvement in a vehicle control device having a running mode in which driving force control and gear shift control are performed without requiring acceleration and deceleration operations by a driver.

Background

In a vehicle having an engine and an automatic transmission that serve as power sources, the following techniques are proposed: during traveling on a sloping road, the automatic transmission is controlled so as to maintain the engine speed higher than during traveling on a flat road. The device described in patent document 1 is an example, and when traveling on an uphill road, the engine speed is maintained at a predetermined high speed by limiting an upshift or a downshift of the automatic transmission regardless of a return operation of an accelerator pedal, thereby improving the reacceleration performance. Patent document 2 describes the following technique: the acceleration feeling is improved by increasing the engine speed more than usual during power loading on an uphill road (in an accelerator depression state).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-76673

Patent document 2: japanese laid-open patent publication No. 2010-90980

Patent document 3: japanese patent laid-open No. 2008-19907

Disclosure of Invention

Problems to be solved by the invention

In recent years, a travel pattern has been proposed in which a target travel state is set without requiring an acceleration or deceleration operation by a driver, such as cruise control (constant speed travel) described in patent document 3, and drive force control and shift control are performed, and in such a travel pattern, it is considered that the engine speed is maintained high on an uphill road in order to ensure predetermined drivability (drive force responsiveness). However, since the driver does not perform acceleration and deceleration operations, the driver's request for drivability is limited, and even if drivability is slightly poor, there is a low possibility that the driver will feel discomfort, which is problematic in conjunction with deterioration of fuel economy caused by setting the engine speed high. In addition, the same problem may occur even when control is performed to maintain the engine speed high by downshifting in order to obtain engine braking on a downhill road.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a vehicle control device having a travel pattern in which driving force control is performed without acceleration/deceleration operation, which can achieve compatibility between drivability on a sloping road and fuel economy.

Means for solving the problems

In order to achieve the object, a first aspect of the invention is a vehicle control device (a) relating to a vehicle having an engine and an automatic transmission as power sources, (b) the vehicle control device being capable of realizing a first travel mode in which driving force control and gear shift control of the automatic transmission are performed in accordance with an acceleration/deceleration operation by a driver, and a second travel mode in which the driving force control and the gear shift control are performed by setting a target travel state without an acceleration/deceleration operation, characterized in that (c) the vehicle has a slope travel control unit that controls the automatic transmission so as to maintain a higher engine speed during traveling on at least one of an uphill road and a downhill road than during traveling on a flat road, and (d) the vehicle is driven in the second travel mode, the slope travel control unit restricts a magnitude of increase in the engine speed compared to that in the first travel mode.

The limitation of the increase width of the engine speed in the second running mode includes a case where the increase width of the engine speed is set to 0 and a case where the engine rotation is stopped. That is, the control of increasing the engine speed during the slope travel by the slope travel control unit may be suspended during the second travel mode.

A second aspect of the present invention is a vehicle control device (a) relating to a vehicle having an engine and an automatic transmission as power sources, and (b) relating to a hybrid vehicle including an electric motor as the power source in addition to the engine, the vehicle being capable of performing a motor running in which the vehicle is driven by only the electric motor with the engine stopped and an engine running in which the vehicle is driven by the power of the engine, (c) the vehicle control device being capable of realizing a first running mode in which a driving force control and a gear shift control of the automatic transmission are performed in accordance with an acceleration/deceleration operation of a driver, and a second running mode in which the driving force control and the gear shift control are performed by setting a target running state without an acceleration/deceleration operation, the vehicle control device being characterized by including a slope running control unit that performs the engine running control and the gear shift control on at least one of an upward slope and a downward slope as compared with a flat road running on the at least one of the upward slope and the downward slope The slope travel control unit controls the automatic transmission so that the engine speed is maintained high, and (e) restricts the increase range of the engine speed in the second travel mode compared to the first travel mode.

A third aspect of the invention provides the vehicle control device of the second aspect, wherein the slope travel control unit starts the engine in the first travel mode, controls the automatic transmission so as to maintain a higher engine speed than in the flat travel mode in the slope travel mode, and stops the engine in the second travel mode.

A fourth aspect of the present invention is a vehicle control device (a) relating to a hybrid vehicle including an engine, a generator rotationally driven by the engine, and a traveling motor that generates power using electric energy obtained by the generator, (b) the vehicle control device being capable of realizing a first traveling mode in which driving force control is performed in accordance with an acceleration/deceleration operation by a driver, and a second traveling mode in which the driving force control is performed by setting a target traveling state without the acceleration/deceleration operation, characterized in that (c) the vehicle has a slope travel control unit that maintains the engine speed higher during a slope travel on at least one of an ascending road and a descending road than during a flat road travel, the slope travel control unit restricts a magnitude of increase in the engine speed compared to that in the first travel mode.

A fifth aspect of the invention is the vehicle control device according to the fourth aspect of the invention, wherein the hybrid vehicle is a series hybrid vehicle in which the engine is a power generation exclusive use.

A sixth aspect of the invention provides the vehicle control device of the fourth or fifth aspect of the invention, wherein the slope travel control unit maintains the engine speed higher on an uphill than on a flat road, and reduces the generated power by the generator on the uphill in the second travel mode to be lower than that on the uphill in the first travel mode.

A seventh aspect of the invention provides the vehicle control device of any one of the fourth to sixth aspects of the invention, wherein the slope travel control unit starts the engine in the first travel mode, maintains the engine rotation speed higher in the slope travel than in the flat travel mode, and stops the engine in the second travel mode.

The eighth aspect of the invention provides the vehicle control device according to any one of the first to seventh aspects of the invention, wherein a follow-up running mode in which a target driving force with which follow-up running can be performed with respect to a preceding vehicle is calculated and the target driving force is made to run as the target running state is provided as the second running mode.

A ninth aspect of the invention provides the vehicle control device according to any one of the first to seventh aspects of the invention, wherein an automatic driving mode in which the target running state is set based on road information and acceleration and deceleration are automatically performed is provided as the second running mode.

A tenth aspect of the invention provides the vehicle control device according to any one of the first to seventh aspects of the invention, wherein (a) a plurality of travel patterns having different degrees of driver's request for acceleration and deceleration are provided as the second travel pattern, and (b) the slope travel control unit reduces the extent of increase in the engine speed to be smaller in the second travel pattern having a smaller degree of request for acceleration and deceleration than in the second travel pattern having a larger degree of request for acceleration and deceleration.

The control for making the increase width of the engine speed small in the second running mode in which the degree of the request for acceleration/deceleration is small also includes a case where the increase width of the engine speed is made 0 and a case where the engine rotation is stopped. That is, in the second running mode in which the degree of the request for acceleration/deceleration is small, the control of increasing the engine speed during the slope running by the slope running control unit may be suspended.

An eleventh aspect of the invention provides the vehicle control device recited in any one of the first to seventh aspects of the invention, wherein (a) as the second travel mode, a follow-up travel mode in which a target drive force with respect to a preceding vehicle is calculated and the preceding vehicle is traveled with the target drive force as the target travel state, and an automatic drive travel mode in which the target travel state is set based on road information and acceleration and deceleration is automatically performed are provided, and (b) in the automatic drive travel mode, the slope travel control unit decreases an increase width of the engine speed to be smaller than that in the follow-up travel mode.

In the follow-up running mode, since the acceleration/deceleration control is performed in accordance with the acceleration/deceleration of the preceding vehicle, it is considered that the degree of request for acceleration/deceleration is greater than that in the automatic driving running mode, and the second running mode in which the degree of request for acceleration/deceleration is greater in the tenth invention can be considered, and the automatic driving running mode can be considered as the second running mode in which the degree of request for acceleration/deceleration is smaller in the tenth invention.

A twelfth aspect of the invention provides the vehicle control device of any one of the first to seventh aspects of the invention, wherein (a) as the second travel mode, an automatic steering travel mode in which travel is performed by automatically controlling a steering angle based on road information, and a manual steering travel mode in which a driver operates the steering angle are provided, and (b) in the automatic steering travel mode, the slope travel control unit decreases a width of increase in the engine speed to be smaller than in the manual steering travel mode.

Effects of the invention

The vehicle control device according to the first, second, and fourth aspects of the invention includes the slope travel control unit that maintains the engine speed higher during the slope travel than during the flat travel, and can obtain excellent drivability during the slope travel, while restricting the increase in the engine speed during the second travel mode than during the first travel mode, thereby improving fuel economy. In the second running mode, since the driver does not perform the acceleration/deceleration operation, the driver's request for acceleration/deceleration is limited, and there is a low possibility that the driver will be given an uncomfortable feeling even if the drivability is slightly deteriorated by limiting the increase width of the engine speed. In particular, when the second travel mode is provided with the automatic driving travel mode in which the target travel state is set based on the road information and the acceleration and deceleration are automatically performed as in the ninth invention, it is considered that it is appropriate for the occupant to prioritize the comfortable ride comfort and the fuel economy over the drivability.

In the tenth aspect of the invention, the magnitude of increase in the engine speed is made smaller in the second running mode in which the degree of demand for acceleration or deceleration is small than in the second running mode in which the degree of demand for acceleration or deceleration is large, so drivability in the second running mode in which the degree of demand for acceleration or deceleration is large can be ensured, and fuel economy can be further improved by making the magnitude of increase in the engine speed small in the second running mode in which the degree of demand for acceleration or deceleration is small. That is, since it is considered that the greater the degree of acceleration/deceleration request (the expected feeling) by the driver, the higher the drivability request by the driver, the greater the increase width of the engine speed than when the degree of acceleration/deceleration request is smaller, and the drivability during the slope running is ensured.

In the eleventh aspect of the invention, when the follow-up running mode and the automatic driving running mode are provided as the second running mode, the extent of increase in the engine speed in the automatic driving running mode is made smaller than that in the follow-up running mode, so drivability in the follow-up running mode can be ensured, and fuel economy can be further improved by making the extent of increase in the engine speed small in the automatic driving running mode. That is, since the follow-up running mode is a preceding vehicle following running mode, it is considered that the driver has a higher degree of request for acceleration and deceleration than the automatic running mode, and the drivability during the slope running is determined by increasing the engine speed to a greater extent than in the automatic running mode.

In the twelfth aspect of the invention, when the second travel mode includes the automatic steering travel mode and the manual steering travel mode, the extent of increase in the engine speed in the automatic steering travel mode is made smaller than that in the manual steering travel mode, so that the drivability in the manual steering travel mode can be ensured, and the extent of increase in the engine speed in the automatic steering travel mode can be made smaller, thereby further improving the fuel economy. That is, in the manual steering travel mode, the driver operates the steering angle, so the degree of contribution of the driving operation is large, and it is considered that the driver has a higher degree of demand for drivability than in the automatic steering travel mode, and therefore the range of increase in the engine speed is made larger than in the automatic steering travel mode to ensure drivability during traveling on a sloping road.

Drawings

Fig. 1 is a schematic diagram for explaining a vehicle drive device for a hybrid vehicle to which the present invention is applied, and is a diagram showing main parts of a control system.

Fig. 2 is an alignment chart illustrating relative rotation speeds of the respective rotation elements of the electrical differential portion of fig. 1.

Fig. 3 is an engagement operation table illustrating a plurality of gear stages of the automatic transmission of fig. 1 and a frictional engagement device for establishing the gear stages.

Fig. 4 is a diagram illustrating an example of input/output signals of an electronic control device provided in the vehicle drive device of fig. 1.

Fig. 5 is a diagram for explaining an example of a shift map used when the step-variable shift control unit of fig. 1 performs shift control of the automatic transmission, and is a diagram showing a power source switching map together.

Fig. 6 is a block diagram specifically illustrating functions related to the drive system executed by the automated driving mode control unit of fig. 1.

Fig. 7 is an example of a time chart illustrating changes in the operating states of the respective units when the up-down slope AI control unit of fig. 1 performs the up-down slope AI control.

Fig. 8 is a flowchart illustrating the operation when the ascending/descending AI control unit restricts the ascending/descending AI control for each travel mode.

Fig. 9 is a diagram illustrating a plurality of simulated gear stages established by a simulated step-up control unit functionally provided in the hybrid control unit of fig. 1.

Fig. 10 is a diagram for explaining a control region of the engine when the simulated gear stage in fig. 9 is established, and is a diagram showing an optimum fuel consumption line together.

Fig. 11 is a flowchart illustrating an operation performed when the simulation hierarchical control unit restricts the simulation hierarchical control for each traveling mode.

Fig. 12 is a schematic diagram for explaining another example of a vehicle drive device for a hybrid vehicle to which the present invention is suitably applied.

Fig. 13 is an engagement operation table for explaining a plurality of gear stages of the automatic transmission of fig. 12 and a frictional engagement device for establishing the gear stages.

Detailed Description

The present invention is suitably applied to a hybrid vehicle having an engine and a motor as power sources, but can also be applied to an engine-driven vehicle having only an engine as a power source. The present invention can be applied to a series hybrid vehicle including an engine dedicated to power generation, a generator, and a motor for traveling, and when the engine speed for power generation is increased on an uphill slope, that is, when the generated power obtained by the generator is increased, the increase range may be changed according to the traveling mode. The engine is an internal combustion engine that generates power by combustion of fuel, such as a gasoline engine or a diesel engine, and a motor generator that can also be used as a generator is suitably used as the electric motor.

As the automatic transmission, a planetary gear type, parallel shaft type, or other stepped automatic transmission or a belt type, or other continuously variable transmission is used in which a plurality of gear stages are established in accordance with the engagement/disengagement state of a plurality of friction engagement devices. The present invention can also be applied to a vehicle including an electric continuously variable transmission in which an input element of a differential mechanism such as a planetary gear device is connected to an engine, a reaction force element is connected to a generator, an output element is connected to a drive wheel, and rotation of the engine is steplessly changed by controlling the rotation speed of the generator to output the rotation from the output element. For example, when the engine is started up on an uphill slope where there is no acceleration request and the driving force is rapidly generated by torque control of the generator at the time of reacceleration, the engine speed may be set lower than that in the first running mode or the engine may be stopped in the second running mode. The engine does not necessarily have to be rotated by itself, and may be rotated by only torque control of the generator. In this case, the idling rotation speed may be equal to or lower than the idling rotation speed.

The target running state of the second running mode is, for example, a target vehicle speed, a target inter-vehicle distance, a target acceleration, a target driving force, a target braking force, a target steering angle, or the like. Specifically, the second travel mode is a constant speed travel mode in which the target drive force is calculated so as to travel at the target vehicle speed set by the driver and the vehicle travels at a substantially constant vehicle speed, a follow-up travel mode in which the target drive force is calculated based on the vehicle-to-vehicle distance between the host vehicle and the preceding vehicle and the follow-up travel is performed at a predetermined target vehicle-to-vehicle distance, an automatic drive travel mode in which the target drive force is calculated based on the target vehicle speed set in sequence such as road information on the travel route and the steering angle is automatically controlled, and the like. The case where the driver operates the steering angle in the constant-speed travel mode and the follow-up travel mode can be regarded as the manual steering travel mode. A case where the vehicle travels by automatically controlling the steering angle in the automatic driving travel mode can be regarded as the automatic steering travel mode. The driving force may be controlled based on the target torque and the target acceleration.

As the automatic driving mode, for example, there is a case where a target vehicle speed is sequentially and automatically set based on map information and travel route information, a target driving force is calculated based on the target vehicle speed, and a steering angle is automatically controlled so as to travel along the travel route. The vehicle may be automatically set to a predetermined position such as a gate according to a predetermined travel route from a parking lot or the like, and various modes may be used. The automated driving mode may be a manned automated driving mode in which a passenger such as a driver is seated, or may be an unmanned automated driving mode in which no passenger is present including the driver. In this specification, a case where a target running state is set based on at least road information and acceleration and deceleration is automatically performed is referred to as an automatic driving mode, and automatic control of a steering angle is not an essential condition. The road information is information such as a road gradient and a curve, and may be obtained from map information or may be acquired by road-to-vehicle communication or the like. Further, acceleration and deceleration may be performed by shooting a lane with a camera.

The slope travel control unit may control the automatic transmission so as to maintain the engine speed higher during travel on at least one of an uphill road and a downhill road than during travel on a flat road, and may control the engine speed to be increased only on either one of the uphill road and the downhill road, or may control the engine speed to be increased on both the uphill road and the downhill road. Further, not only the upshift of the automatic transmission is restricted, but also the downshift may be performed to positively increase the engine speed.

A vehicle control device relates to a vehicle having (a) an electric differential unit capable of continuously changing the rotational speed of an engine by torque control of a differential rotary machine and transmitting the speed to an intermediate transmission member and (b) a plurality of gear stages established as an automatic transmission disposed between the intermediate transmission member and drive wheels and capable of mechanically changing the speed ratio of the rotational speed of the intermediate transmission member to the output rotational speed, and the vehicle control device has (c) a simulated stepped control unit that controls the electric differential unit so that a plurality of simulated gear stages having different gear ratios of the engine speed to the output speed of the automatic transmission are established, (d) in order to suppress deterioration of fuel economy due to the gradation of the simulation, it is preferable to limit the gradation of the simulation in the second running mode as compared with the first running mode. Specifically, the control region of the engine operation is narrowed to approach the optimum fuel economy line during the simulation staging, and the simulation staging may be stopped during the second running mode.

Examples

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Fig. 1 is a main point view of a vehicle drive device 10 for a hybrid vehicle to which the present invention is applied, and is a diagram showing main portions of a control system. The vehicle drive device 10 includes an engine 12, an electric differential unit 14, and an automatic transmission 16 connected in series. The engine 12 is an internal combustion engine such as a gasoline engine or a diesel engine, and the output is controlled by an engine output control device 40. The engine output control device 40 includes, for example, an electronic throttle valve 100, a fuel injection device 102, an ignition device 104, and the like shown in fig. 4, and electrically controls the engine output by controlling the electronic throttle valve 100, the fuel injection device 102, the ignition device 104, and the like in accordance with control signals supplied from the electronic control device 50. The electric differential portion 14 includes a single-pinion type planetary gear device 18 as a differential gear mechanism. The planetary gear device 18 includes a carrier CA0 coupled to the engine 12, a sun gear S0 coupled to the first motor generator MG1, and a ring gear R0 coupled to the intermediate transmission member 20 so as to be capable of differential rotation, and the intermediate transmission member 20 is coupled to the second motor generator MG 2. The electric differential portion 14 and the automatic transmission 16 are configured substantially symmetrically with respect to the axial center thereof, and therefore the lower half portions thereof are omitted in the schematic diagram of fig. 1.

Fig. 2 is an alignment chart in which the rotation speeds of three rotation elements S0, CA0, and R0 of the electric differential portion 14 can be connected in a straight line, rotation speed Nmg1 of sun gear S0 is the rotation speed of first motor generator MG1 (MG1 rotation speed), rotation speed Ne of carrier CA0 is the rotation speed of engine 12 (engine rotation speed), rotation speed Nmg2 of ring gear R0 is the rotation speed of second motor generator MG2 (MG2 rotation speed), and MG2 rotation speed Nmg2, which is the differential output rotation speed with respect to the differential input rotation speed Ne, can be continuously and steplessly changed by regenerative torque control and power running torque control of first motor generator MG1 and second motor generator MG 2. That is, the electrical differential unit 14 functions as an electrical continuously variable transmission capable of continuously changing the gear ratio γ 0 (Ne/Nmg 2), and the first motor generator MG1 functions as a differential rotary machine. Further, the carrier CA0 coupled to the engine 12 is an input element, the sun gear S0 coupled to the first motor generator MG1 is a reaction force element, and the ring gear R0 coupled to the intermediate transmission member 20 is an output element. The first motor generator MG1 and the second motor generator MG2 are connected to the rechargeable power storage device 24 via the inverter 22, and electrically control the motor torques of the first motor generator MG1 and the second motor generator MG2 in accordance with a motor control signal supplied from the electronic control device 50. These motor generators MG1 and MG2 each function as a motor and a generator, and the first motor generator MG1 mainly functions as a generator to generate a reaction force, and the second motor generator MG2 mainly functions as a motor to output a driving force. The engine 12, the electrical differential portion 14, and the second motor generator MG2 function as power sources of the vehicle drive device 10. In the present embodiment, the engine 12, the first motor generator MG1, and the second motor generator MG2 are directly coupled to the carrier CA0, the sun gear S0, and the ring gear R0, respectively, but a transmission gear, a clutch, and the like may be interposed therebetween.

The automatic transmission 16 is a planetary gear type stepped transmission, and changes the speed of rotation of the intermediate transmission member 20 to output the rotation from an output shaft 32. Specifically, the present invention includes a single-pinion type first planetary gear device 26, a single-pinion type second planetary gear device 28, and a single-pinion type third planetary gear device 30, and two clutches C1 and C2 and three brakes B1, B2, and B3 (hereinafter, simply referred to as "clutch C" and "brake B" unless otherwise specified) are provided as hydraulic friction engagement devices. As shown in the engagement operation table of fig. 3, by engaging any two of the clutches C and brakes B, four forward gear stages 1st to 4th and a reverse gear stage R (reverse gear) different in the speed ratio γ 1 (Nmg 2/Nout) which is the ratio of the rotation speed Nmg2 of the intermediate transmission member 20 to the rotation speed (output rotation speed) Nout of the output shaft 32 can be established, and by releasing both of them, the power transmission is cut off to N (neutral). The clutches C and the brakes B are engaged by receiving hydraulic pressure supply from the hydraulic control circuit 42, and are electrically controlled by an AT solenoid valve 106 (see fig. 4) or the like of the hydraulic control circuit 42 in accordance with a shift control signal supplied from the electronic control device 50, thereby controlling the engagement and release of the clutches C and the brakes B. The AT solenoid valves 106 are disposed in the clutch C and the brake B, respectively, for example. The output shaft 32 is coupled to left and right drive wheels 36 via a final reduction gear 34.

In the vehicle drive device 10, the electrical differential portion 14 and the automatic transmission 16 can be used as a whole to perform the continuously variable transmission control. Also, by controlling the MG1 rotation speed Nmg1 and the like so that the gear ratio of the electrical differential portion 14 is constant, the same shift control as the stepped shift can be performed as a whole. In either case, during the gear shift of the automatic transmission 16, the rotational speeds of the respective portions of the electrical differential portion 14, for example, the MG1 rotational speed Nmg1 and the like are controlled in accordance with the change in the rotational speed of the intermediate transmission member 20 accompanying the gear shift in order to perform the gear shift quickly and smoothly.

The vehicle drive device 10 of the present embodiment further includes an automatic brake system 44 and an automatic steering system 46. The automatic brake system 44 electrically controls brake fluid pressure, which is braking force of each wheel brake 38 provided on the drive wheels 36 and driven wheels (non-drive wheels), not shown, in accordance with a brake control signal supplied from the electronic control device 50. Further, by pedaling a brake pedal, not shown, brake fluid pressure is also supplied to the wheel brakes 38 via the brake master cylinder, and the wheel brakes 38 mechanically generate braking force corresponding to the brake fluid pressure, i.e., the brake operation force Brk. The automatic steering system 46 electrically controls the steering angle Φ by an electric motor or the like in accordance with a steering angle control signal supplied from the electronic control device 50. The steering angle Φ may be a rotation angle of the steering wheel or an angle of the steered wheel.

The electronic control device 50 functions as a controller for performing various controls of the vehicle drive device 10 of the present embodiment, such as output control of the engine 12, motor torque control of the motor generators MG1, MG2, gear shift control of the automatic transmission 16, braking force control by the automatic braking system 44, steering control by the automatic steering system 46, and the like, and is configured to include a microcomputer having a CPU, a ROM, a RAM, an input/output interface, and the like, and to execute signal processing by using a temporary storage function of the RAM in accordance with a program stored in the ROM in advance. If necessary, the engine control system may be configured separately from the electric motor control system, the shift control system, and the like.

Fig. 4 illustrates signals input to the electronic control device 50 and signals output from the electronic control device 50, and when a part of the signals is specifically described, the electronic control device 50 is connected to an engine rotation speed sensor 70, an MG1 resolver (rotation speed sensor) 72, an MG2 resolver (rotation speed sensor) 74, an output rotation speed sensor 76, a foot brake sensor 78, an accelerator operation amount sensor 80, a steering angle sensor 82, and a vehicle acceleration sensor 83, and is supplied with signals indicating an engine rotation speed Ne, an MG1 rotation speed Nmg1, an MG2 rotation speed Nmg2, a rotation speed (output rotation speed) Nout of the output shaft 32, a depression operation force (brake operation force) Brk of a brake pedal, a depression operation amount (accelerator operation amount) of the accelerator pedal, a steering angle Φ, and a vehicle acceleration G, respectively. The output rotation speed Nout corresponds to the vehicle speed V.

The auto cruise setting switch 84 is a device that performs an operation of selecting a cruise travel mode for constant speed travel or follow-up travel without an operation of accelerating or decelerating the vehicle by the driver, a setting of the target vehicle speed VtagC, an increase or decrease in the target vehicle speed VtagC, a setting of the target inter-vehicle distance DtagC during follow-up travel, and the like, and is disposed on, for example, a steering wheel or the like, and supplies signals indicating the target vehicle speed VtagC, the target inter-vehicle distance DtagC, and the like to the electronic control device 50. The navigation System 86 includes map Information, sets a travel route according to a destination, displays the map and the travel route on a display device disposed on an instrument panel or the like, acquires various road traffic Information such as a Vehicle position, a traffic jam, a road gradient, an altitude, a legal speed, signal Information, and weather by using GPS (Global Positioning System) and VICS (registered trademark) (Vehicle Information and Communication System), Vehicle-to-Vehicle Communication, road-to-Vehicle Communication, and the like, and supplies a signal indicating the Information to the electronic control device 50. An operation member capable of performing various selection operations, setting operations, and the like by a touch operation, a press operation, a rotation operation, and the like is provided on the display device or in the vicinity thereof. An information communication device that receives information from the outside may be provided independently of the navigation system 86 as needed. The radar 88 detects the inter-vehicle distance between the host vehicle and the front vehicle and the rear vehicle, the nearby pedestrians, or the distance between the host vehicle and the obstacle, and supplies a signal indicating the information to the electronic control device 50. The camera 90 is a movie camera, a still camera, or the like that photographs other vehicles, pedestrians, obstacles, traffic signals, lanes, guard rails, parking positions, predetermined signs, or the like, which are present in front of, behind, on the side of, or the like of the vehicle, and a signal indicating image information thereof is supplied to the electronic control device 50.

The manned automatic drive switch 92 is a switch for selecting an automatic drive mode in which the vehicle is driven by automatically controlling the drive force and the steering angle Φ of the vehicle in a state where the driver or the passenger is seated, and the unmanned automatic drive switch 94 is a switch for selecting an automatic drive mode in which the vehicle is driven by automatically controlling the drive force and the steering angle Φ of the vehicle in a state where the driver or the passenger is not seated. The unmanned automatic driving switch 94 incorporates, for example, a wireless key for wirelessly locking and unlocking a door lock of a vehicle. In these automatic driving, for example, a target vehicle speed is sequentially and automatically set based on map information, travel route information, various road traffic information, and the like, a target driving force is calculated based on the target vehicle speed, and the steering angle Φ is automatically controlled so as to travel along the travel route. The vehicle may be automatically dispatched to a predetermined position such as a gate according to a predetermined travel route from a parking lot or the like, and various forms are possible. The unmanned automatic driving mode is suitable for parking, calling out from a parking place, and the like. The unmanned autonomous driving mode is also suitable for use in, for example, a case where a platoon driving (follow-up driving) is performed after a leading vehicle ahead. The manned automatic driving switch 92 and the unmanned automatic driving switch 94 may be incorporated into the navigation system 86, and the navigation system 86 may be designed to select the manned automatic driving mode or the unmanned automatic driving mode. As for the automatic cruise setting switch 84, a part or all of the functions may be incorporated into the navigation system 86.

An engine control signal is output from the electronic control device 50 to an engine output control device 40 (see fig. 1) that controls an engine output, and the throttle opening of the electronic throttle valve 100 of the engine 12, the fuel supply amount of the fuel injection device 102, the ignition timing of the engine 12 by the ignition device 104, and the like are electrically controlled. The first motor generator MG1 and the second motor generator MG2 output motor control signals to the inverter 22 to electrically control the motor torques thereof individually. A shift control signal is output to the AT solenoid valve 106 of the hydraulic control circuit 42, and the engagement and release of the clutch C and the brake B are controlled, respectively, to electrically establish a predetermined gear stage of the automatic transmission 16. The brake control signal is output to the automatic brake system 44 to electrically control the braking force of the wheel brakes 38. A steering angle control signal is output to the automatic steering system 46, and the steering angle Φ is electrically controlled by an electric motor or the like.

As shown in fig. 1, the electronic control device 50 functionally includes a hybrid control unit 52, a stepped shift control unit 54, a steering control unit 56, a brake control unit 58, an automatic driving travel mode control unit 60, a cruise travel mode control unit 62, a driving operation travel mode control unit 64, and an up-down-slope AI (artificial only) control unit 66. The hybrid control unit 52 calculates a target engine output based on the transmission loss of each part, the auxiliary load, the gear ratio γ 0 of the electric differential unit 14, the assist torque of the second motor generator MG2, the gear stage (gear ratio γ 1) of the automatic transmission 16, and the like so as to drive the vehicle by the target driving force Ftag2 supplied from the automated driving mode control unit 60, and controls the engine 12 via the engine output control device 40 so that the engine speed Ne and the engine torque Te of the target engine output can be obtained. The gear ratio γ 0 of the electric differential portion 14 is determined so that the engine 12 operates in an efficient operating region, for example, on an optimum fuel economy line shown in fig. 10. In the case of the unmanned or manned autonomous driving mode, the target driving force Ftag2 is set successively based on various road traffic information such as legal speed and road gradient, etc. such as the target vehicle speed calculation unit 112, the F/F (feedforward) control calculation unit 132, the F/B (feedback) control calculation unit 134, and the driving force adjustment unit 138 of fig. 6, which describe the function of the autonomous driving mode control unit 60, so as to travel along a predetermined travel route. Further, in the constant speed running in the cruise running mode, the target driving force Ftag2 is set successively so as to run at the preset target vehicle speed VtagC, and in the follow-up running mode in the cruise running mode, the target driving force Ftag2 is set successively so as to run at the preset target inter-vehicle distance DtagC. In the driving operation running mode in which the driving force is controlled in accordance with the acceleration/deceleration operation (accelerator operation, brake operation) of the driver, the target driving force FtagM is successively calculated from the accelerator operation amount Acc, the vehicle speed V, and the like, and the target driving force Ftag2 is set based on the target driving force FtagM. The cruise travel mode control unit 62 sets the target vehicle speed VtagC and the target vehicle-to-vehicle distance DtagC based on a signal from the auto cruise setting switch 84, and the driving operation travel mode control unit 64 sequentially calculates the target driving force FtagM based on the accelerator operation amount Acc and the vehicle speed V. The target inter-vehicle distance DtagC is selected from three stages, i.e., large, medium, and small, and is variably set according to the vehicle speed V, and the cruise travel mode control unit 62 calculates the target driving force FtagC by feedback control or the like so that the actual inter-vehicle distance D between the own vehicle and the preceding vehicle detected by the radar 88 becomes the target inter-vehicle distance DtagC, and sets the target driving force Ftag2 based on the target driving force FtagC. When the target driving force Ftag2 is negative, the engine brake and the regenerative control of the second motor generator MG2 generate the power source brake, and the power source brake is added to the braking force of the wheel brake 38 controlled by the brake control unit 58 to obtain the target driving force Ftag 2. The electronic control device 50 functions as a vehicle control device capable of running in a plurality of running modes.

Hybrid control unit 52 also stops engine 12 or sets it to an idle state in a low output torque range or a low vehicle speed range where engine efficiency is considered to be relatively poor, and switches the power source according to a predetermined power source map so that the vehicle runs using only second motor generator MG2 as the power source. The one-dot chain line shown in the lower left portion (a low-driving-force and low-vehicle-speed region) of fig. 5 is an example of the power source switching map, and is determined based on the vehicle speed V and the driving force, and the low-vehicle-speed and low-driving-force region is set as the motor travel region, and the power source switching control is executed by starting or stopping the engine 12, or the like. The actual driving force may be estimated from the engine torque, the motor torque, the gear stage of the automatic transmission 16, and the like, but it is preferable to use the target driving force Ftag2 calculated by the automated driving mode control unit 60. Although not shown, a hysteresis (hysteresis) is provided between the switching line for switching from the motor running to the engine running and the switching line for switching from the engine running to the motor running in order to prevent frequent replacement. Also, even during engine running in which the engine 12 is used as a power source for running, the electric energy from the first motor generator MG1 subjected to the regeneration control and/or the electric energy from the power storage device 24 are supplied to the second motor generator MG2, and the second motor generator MG2 is driven (power running control) to apply torque to the drive wheels 36, thereby performing torque assist for assisting the power of the engine 12. That is, in the engine running region of fig. 5, torque assist by second motor generator MG2 is performed as needed.

The stepped shift control unit 54 performs shift control of the automatic transmission 16 according to a predetermined shift map, and performs engagement and release control of the clutch C and the brake B via the AT solenoid valve 106 of the hydraulic control circuit 42 so that the target gear stage obtained according to the shift map is established. The shift map is a shift condition set based on the driving force and the vehicle speed V, for example, as shown in fig. 5, and is determined so as to switch to a gear stage on the high speed side with a smaller gear ratio γ 1 as the vehicle speed V becomes higher, and to switch to a gear stage on the low speed side with a larger gear ratio γ 1 as the driving force becomes higher. As the driving force, for example, the target driving force Ftag2 calculated by the automated driving mode control unit 60 is used. The solid lines in fig. 5 are upshift lines, and the broken lines are downshift lines, with a prescribed hysteresis provided therebetween.

When the autonomous driving mode with or without a person is selected, the steering control unit 56 controls the automatic steering system 46 so that the target steering angle Φ tag supplied from the autonomous driving mode control unit 60 is obtained. The target steering angle Φ tag is determined based on road information or the like, and is set as appropriate in accordance with the vehicle speed V, the driving force, or the like, for example, to travel along a predetermined travel route, travel along a lane or the like detected by the camera 90, or switch lanes, to perform parking or tandem parking based on parking position information detected by the camera 90, or to avoid contact with a pedestrian or an obstacle detected by the radar 88 or the camera 90. Fig. 6 is a diagram for explaining the functions of the drive system of the automated driving mode control unit 60, and the steering control is omitted. The automatic steering mode in which the steering control unit 56 controls the automatic steering system 46 so as to achieve the target steering angle Φ tag in this way is the automatic steering mode, and the cruise mode in which the steering control unit 56 does not automatically control the steering angle Φ is the manual steering mode.

When the automated driving mode with or without a person is selected, the brake control unit 58 controls the automatic brake system 44 such that the wheel brakes 38 are operated according to the target braking force Btag supplied from the automated driving mode control unit 60. The target braking force Btag is appropriately set so as to decelerate at a predetermined deceleration rate by a target vehicle-to-vehicle distance calculation unit 116, an actual vehicle-to-vehicle distance calculation unit 118, a vehicle speed safety margin calculation unit 114, a target braking force calculation unit 140, and the like shown in fig. 6, in order to stop at a predetermined stop position, stop in accordance with signal information (red light) detected by the camera 90 or input from the outside, secure a vehicle-to-vehicle distance between the vehicle and the preceding vehicle detected by the radar 88, or avoid collision with a pedestrian or an obstacle detected by the radar 88 and the camera 90. In the cruise running mode in which the constant-speed running or the follow-up running is performed, or in the driving operation running mode in which the driving force is controlled in accordance with the acceleration/deceleration operation of the driver, the target braking force Btag may be set under a certain condition such as collision avoidance, and the wheel brakes 38 may be forcibly operated.

As shown in fig. 6, the drive system includes the automated driving travel mode control unit 60 functionally including a travel plan generation unit 110 and a travel control unit 130. The travel plan generating unit 110 includes a target vehicle speed calculating unit 112, a vehicle speed safety margin calculating unit 114, a target inter-vehicle distance calculating unit 116, and an actual inter-vehicle distance calculating unit 118, and supplies vehicle position information, map information such as a road, a gradient, an altitude, and a legal speed, infrastructure information, a travel route, a travel road, and weather information from the navigation system 86 to the target vehicle speed calculating unit 112. The navigation system 86 can set a destination, a travel route, and the like by the driver, and can set coordinated driving in which an operation by the driver is added to automated driving, time priority, fuel economy priority, an upper limit vehicle speed, a desired vehicle speed, and the like. The infrastructure information is information of a road, a signal, and the like supplied from an information communication device provided in the road, the signal, and the like. The target vehicle speed calculation unit 112 sequentially sets the target vehicle speed Vtag1, which is a basis for performing automated driving, based on these pieces of information. The cruise travel mode control unit 62 supplies the target vehicle speed VtagC during constant speed travel to the target vehicle speed calculation unit 112, and sets the target vehicle speed VtagC as the target vehicle speed Vtag1 in the cruise travel mode.

The vehicle speed safety margin calculation unit 114 obtains a vehicle speed safety margin Vm from the difference between the target vehicle-to-vehicle distance Dref determined by the target vehicle-to-vehicle distance calculation unit 116 and the actual vehicle-to-vehicle distance D calculated by the actual vehicle-to-vehicle distance calculation unit 118 based on a signal from the radar 88 or the like, and calculates a target vehicle speed Vtag2 by subtracting the vehicle speed safety margin Vm from the target vehicle speed Vtag 1. The target inter-vehicle distance Dref and the actual inter-vehicle distance D are inter-vehicle distances between the own vehicle and the preceding vehicle, and the target inter-vehicle distance Dref is set to a distance sufficient to avoid a collision with the preceding vehicle, based on the current vehicle speed V and the like. When the actual vehicle-to-vehicle distance D is greater than the target vehicle-to-vehicle distance Dref, a vehicle speed safety margin Vm is set to 0 to perform lower limit protection in order to prevent unnecessary increase in the vehicle speed V. The vehicle speed safety margin Vm may be determined based on the distance between the own vehicle and the pedestrian, the obstacle, or the side vehicle predicted to come ahead, in addition to the preceding vehicle.

The travel control unit 130 includes an F/F (feedforward) control arithmetic unit 132, an F/B (feedback) control arithmetic unit 134, a travel resistance arithmetic unit 136, a driving force adjustment unit 138, and a target braking force arithmetic unit 140. The F/F control arithmetic unit 132 calculates an FF driving force value Fff required for traveling at the target vehicle speed Vtag2 in accordance with a predetermined feed-forward control method or the like, and the F/B control arithmetic unit 134 calculates an FB correction value Ffb in accordance with a predetermined feedback control method or the like based on a deviation Δ V between the target vehicle speed Vtag2 and the current vehicle speed V. The running resistance calculation unit 136 calculates a running resistance Fr based on the road load (R/L), the road gradient, the number of passengers, the load, and the like of the vehicle, and calculates a basic target driving force Ftag1 by adding the FF driving force value Fff, the FB correction value Ffb, and the running resistance Fr. The road load may be preset in the navigation system 86 or the like, but may be downloaded through a communication circuit, or calculated from the actual driving force F, the road gradient, the vehicle speed V, or the like.

The driving force adjustment unit 138 adjusts the target driving force Ftag1 according to the running mode to set the final target driving force Ftag 2. The driving force adjustment unit 138 is supplied with the target driving force FtagC calculated so as to perform the follow-up running in accordance with the target inter-vehicle distance Dtag from the cruise running mode control unit 62, and the driving force adjustment unit 138 is supplied with the target driving force FtagM calculated based on the accelerator operation amount Acc, the vehicle speed V, and the like from the driving operation running mode control unit 64, and the target driving force Ftag1 based on these target driving forces FtagC, FtagM is used in the cruise running mode and the driving operation running mode. For example, in the unmanned autonomous driving mode, it is preferable to prioritize fuel economy over drivability, in the manned autonomous driving mode, it is preferable to prioritize ride comfort over drivability, in the cruise mode, it is preferable to ensure drivability to some extent, and in the driving operation mode, it is preferable to prioritize drivability over fuel economy. Therefore, for example, regarding the change rate that is the maximum value of the change rate of the target driving force Ftag1, the target driving force Ftag2 is set in accordance with the target driving force Ftag1 in the driving operation running mode with the change rate maximized or without limitation. In the cruise travel mode, the target driving force Ftag2 is set by limiting the target driving force Ftag1 at a rate of change smaller than that in the driving operation travel mode, in the manned automated travel mode, the target driving force Ftag2 is set by limiting the target driving force Ftag1 at a rate of change smaller than that in the cruise travel mode, and in the unmanned automated travel mode, the target driving force Ftag2 is set by limiting the target driving force Ftag1 at a rate of change smaller than that in the manned automated travel mode.

The target driving force Ftag2 is supplied to the target braking force calculation unit 140 and is output to the hybrid control unit 52 and the stepped shift control unit 54. When the target driving force Ftag2 is negative, the target braking force calculation unit 140 calculates a target braking force Btag of the wheel brake 38 that is added to the power source braking by the hybrid control unit 52 to obtain the target driving force Ftag2, and supplies the target braking force Btag to the brake control unit 58. By controlling the automatic brake system 44 in accordance with the target braking force Btag, the wheel brakes 38 are operated at the target braking force Btag, and the power source braking obtained under the control of the hybrid control portion 52 is added to obtain the target driving force Ftag 2.

Returning to fig. 1, the upward and downward slope AI control unit 66 controls the automatic transmission 16 so as to maintain the engine rotation speed Ne higher during traveling on both the upward slope road and the downward slope road than during traveling on a flat road. For example, when the driving force is reduced in a curve or the like on an uphill road, the drivability at the time of reacceleration is improved by limiting the upshift based on the shift map of fig. 5 to maintain the engine rotation speed Ne at a high rotation speed, and at the time of power application on an uphill road, the shift map of fig. 5 is shifted to a low driving force side or a high vehicle speed side to facilitate downshift or forcibly downshift to increase the engine rotation speed Ne and improve the uphill performance. When the driving force decreases on a downhill, the engine speed Ne is increased and the engine brake is increased by restricting the upshift or forcibly performing the downshift based on the shift map of fig. 5. The engine rotation speed Ne may be increased not only by the shift control of the automatic transmission 16 but also by the shift control using the electric differential portion 14 together. The solid line in fig. 7 is an example of a time chart when the engine rotation speed Ne is maintained high by the uphill/downhill AI control unit 66 when the driving force is reduced at a curve or the like of an uphill road, and the time t1 is a time when the road gradient is equal to or greater than a predetermined value and the uphill/downhill control flag is activated. The road gradient can be calculated from, for example, the vehicle acceleration G, the engine torque, the motor torque, and the like, but may be detected by a gradient sensor or the like, or may be read from map information and road information. When the target driving force Ftag2 decreases at time t2, the shift control is performed according to the shift map of fig. 5, the automatic transmission 16 is shifted up and the engine rotation speed Ne decreases as shown by the broken line in fig. 7, but in the present embodiment, the engine rotation speed Ne is maintained at a high rotation speed by prohibiting the shift up as shown by the solid line. The up-down AI control unit 66 corresponds to a slope travel control unit.

The ascending/descending AI control unit 66 further includes a limiting unit that limits ascending/descending AI control according to the driving mode, and executes signal processing in accordance with steps S1 to S11 (hereinafter, simply referred to as S1 to S11) of the flowchart of fig. 8. In S1 of fig. 8, it is determined whether or not the automated driving mode is selected based on whether or not any of the manned automated driving switch 92 and the unmanned automated driving switch 94 has been turned on. If the automated driving mode is selected, S2 is executed to determine whether the automated driving mode is selected based on whether the unmanned automatic driving switch 94 is turned on. When the unmanned automatic driving switch 94 is turned on, it is determined at S4 that the unmanned automatic driving mode is selected, and when the unmanned automatic driving switch 94 is not turned on, it is determined at S5 that the manned automatic driving mode is selected. If the determination at S1 is no (negative), that is, if the auto-drive running mode is not selected, S3 is executed to determine whether the cruise running mode is selected based on whether or not the selection operation is performed by the auto-cruise setting switch 84. When the selection operation is performed by the auto cruise setting switch 84, it is determined at S6 that the cruise travel mode is selected, and when the selection operation is not performed by the auto cruise setting switch 84, it is determined at S7 that the normal travel mode, that is, the driving operation travel mode in which the driving force control and the gear shift control are performed in accordance with the acceleration and deceleration operation by the driver and the steering angle Φ is changed in accordance with the steering operation, is selected. The above-described unmanned automatic drive running mode, manned automatic drive running mode, and cruise running mode are all second running modes in which the driving force control and the speed change control are performed by setting the target running state (target vehicle speed, target inter-vehicle distance, target driving force, target steering angle, and the like) without acceleration and deceleration operations, and the driving operation running mode is the first running mode in which the driving force control and the speed change control are performed in accordance with the acceleration and deceleration operations of the driver.

When it is determined at S4 that the unmanned autonomous driving mode is selected, limit 1 is set at S8, when it is determined at S5 that the manned autonomous driving mode is selected, limit 2 is set at S9, when it is determined at S6 that the cruise driving mode is selected, limit 3 is set at S10, and when it is determined at S7 that the driving operation mode is selected, no limit is set at S11. The restrictions 1 to 3 set in S8 to S10 are set so that the increase width of the engine rotation speed Ne is different from that during flat road running and satisfies the relationship of restriction 1< restriction 2< restriction 3. That is, if the increase width of the engine rotation speed Ne is increased by the restriction of the upshift or the execution of the downshift, the acceleration performance and the reacceleration performance on the uphill road are improved, or a large engine braking force can be obtained on the downhill road, but the fuel economy is impaired by the increase of the engine rotation speed Ne, and therefore the increase width is restricted depending on the running mode to achieve the harmonization with the fuel economy. Specifically, the smaller the degree of request for acceleration/deceleration on the up-down slope (the degree of driver's expectation), the smaller the increase width of the engine rotation speed Ne to improve the fuel economy, while the larger the degree of request for acceleration/deceleration on the up-down slope, the larger the increase width of the engine rotation speed Ne to obtain appropriate drivability. The magnitude of increase in the engine rotation speed Ne can be varied in accordance with the number of steps of upshift and downshift of the automatic transmission 16, and the engine rotation speed Ne can be more finely controlled by the continuously variable transmission control of the electrical differential portion 14.

In the unmanned autonomous traveling mode, since the occupant is absent and the degree of acceleration and deceleration required is not considered as compared with the manned traveling mode, the fuel economy can be improved by reducing the increase width of the engine rotation speed Ne. The up-down slope AI control may be suspended with the increase of the engine speed Ne to 0. In the manned autonomous driving mode in which the occupant is present, the degree of the acceleration/deceleration request is greater than in the unmanned autonomous driving mode, and therefore it is preferable to increase the engine rotation speed Ne to ensure the acceleration/deceleration performance. However, since the degree of the request for acceleration/deceleration is lower than the cruise travel mode and the driving operation travel mode, limit 2 is set such that the increase width of engine rotation speed Ne is smaller than those of the travel modes. In the cruise travel mode, since the vehicle travels at the target vehicle speed Vtag or follows the preceding vehicle at the target inter-vehicle distance Dtag, the degree of acceleration/deceleration required is higher than in the automatic travel mode, and the limit 3 is set such that the increase width of the engine rotation speed Ne is larger than in the manned automatic travel mode. However, since the degree of the request for acceleration/deceleration is lower than the driving operation running pattern in which the driver performs acceleration/deceleration in real time, the increase width of the engine rotation speed Ne can be made smaller than the driving operation running pattern. In the driving operation running mode, since the driver himself or herself requests acceleration/deceleration, excellent drivability is required for acceleration/deceleration even on an ascending/descending road, and it is preferable to perform the ascending/descending AI control without restriction.

The degree of acceleration/deceleration request for the ascending/descending road (the driver's expectation) also corresponds to the degree of driver's driving operation contribution, and it is generally considered that the smaller the degree of driving operation contribution, the smaller the degree of acceleration/deceleration request. For example, it is considered that the unmanned automatic running mode and the manned automatic running mode in which the steering angle Φ is automatically controlled have a lower degree of demand for drivability than the cruise running mode in which the steering angle Φ is operated by the driver, and from this point of view, it is also preferable to increase the engine rotation speed Ne in the unmanned automatic running mode and the manned automatic running mode to a smaller extent than the cruise running mode to improve fuel economy.

Further, although the range of increase in the engine rotation speed Ne during the up-down slope running is set in each of the running modes described above, for example, in the case of the follow-up running mode in the cruise running mode, acceleration/deceleration may be predicted based on the inter-vehicle distance D and the vehicle speed V, and the range of increase in the engine rotation speed Ne may be increased in the case where the possibility of acceleration/deceleration is high. That is, when the vehicle-to-vehicle distance D is short and the vehicle speed V is high, it can be predicted that the possibility of a need for rapid acceleration/deceleration is high, and therefore the increase width of the engine rotation speed Ne is increased. In other travel modes, the increase width of the engine rotation speed Ne during traveling on an up-down slope can be changed based on the inter-vehicle distance D, the vehicle speed V, and the like.

Returning to fig. 1, the hybrid control unit 52 functionally includes a simulated step control unit 68. The simulated stepped control unit 68 controls the electrical differential unit 14 so as to establish a plurality of simulated gear steps having different gear ratios γ 2 (Ne/Nout) of the engine rotation speed Ne with respect to the output rotation speed Nout, where the gear ratio γ 2 is a value obtained by multiplying the gear ratio γ 0 of the electrical differential unit 14 by the gear ratio γ 1 of the automatic transmission 16 (γ 2 ═ γ 0 × γ 1). For example, as shown in fig. 9, a plurality of simulated gear stages can be established by controlling the engine rotation speed Ne by the first motor generator MG1 in accordance with the output rotation speed Nout in such a manner that each gear ratio γ 2 can be maintained. Fig. 9 shows a case where a ten-speed shift having a simulated first-speed gear stage to a simulated ten-speed gear stage as a plurality of simulated gear stages is possible, and the same driving performance and driving feeling such as engine noise as those of the mechanical stepped transmission are obtained as a whole. In this case, the engine 12 changes the engine torque and the engine rotation speed Ne within the range of the simulated stepped control region indicated by the oblique lines in fig. 10.

The simulation hierarchical control unit 68 further includes a limiting unit that limits simulation hierarchical control according to the driving mode, and executes signal processing according to steps R1 to R11 (hereinafter, simply referred to as R1 to R11) of the flowchart of fig. 11. The travel mode is determined in R1 to R7 in fig. 11 in the same manner as in S1 to S7 in fig. 8. The judgment results from S4 to S7 may be read. When it is determined at R4 that the unmanned autonomous driving mode is selected, limit 1 is set at R8, when it is determined at R5 that the manned autonomous driving mode is selected, limit 2 is set at R9, when it is determined at R6 that the cruise driving mode is selected, limit 3 is set at R10, and when it is determined at R7 that the driving operation mode is selected, no limit is set at R11. The restrictions 1 to 3 set in R8 to R10 are different in the control region (hatched portion in fig. 10) in which the engine 12 is operated during the simulation of the stepped state, and are set so that the range of the control region satisfies the relationship of restriction 1< restriction 2< restriction 3. That is, if the control region of the engine 12 is increased by simulating the stepped increase, the engine rotation speed Ne is greatly changed at the time of shifting, and the same driving feeling (drivability, engine noise, etc.) as that of the stepped transmission can be obtained, but on the other hand, the fuel economy is impaired by the deviation from the optimum fuel economy line, and therefore the control region is limited according to the traveling mode, and the fuel economy is harmonized. Specifically, the smaller the degree of request for acceleration/deceleration (the degree of expectation of the driver), the smaller the control range of the engine 12 is made to improve the fuel economy, while the larger the degree of request for acceleration/deceleration, the larger the control range of the engine 12 is made to obtain appropriate drivability.

In the unmanned autonomous driving mode, since the occupant is absent and the degree of acceleration and deceleration required is not considered as compared with the manned driving, the control range of the engine 12 can be reduced to improve the fuel economy. The analog staging control may also be discontinued to operate the engine 12 on the optimal fuel economy line. In the manned autonomous driving mode in which the occupant is present, the degree of the acceleration/deceleration request is greater than in the unmanned autonomous driving mode, and therefore it is preferable to increase the driving feeling by increasing the control region of the engine 12. However, since the degree of the request for acceleration/deceleration is lower than the cruise travel mode and the driving operation travel mode, limit 2 in which the control region of engine 12 is narrower than these travel modes is set. In the cruise travel mode, since the vehicle travels at the target vehicle speed Vtag or the following travel is performed with respect to the preceding vehicle at the target inter-vehicle distance Dtag, the degree of the acceleration/deceleration request is higher than in the automatic drive travel mode, and the limit 3 in which the control region of the engine 12 is larger than in the manned automatic drive travel mode is set. However, since the degree of the request for acceleration/deceleration is lower than the driving operation running pattern in which the driver performs acceleration/deceleration in real time, the control region of the engine 12 may be smaller than the driving operation running pattern. In the driving operation running mode, since the driver himself or herself requests acceleration or deceleration, it is preferable to obtain excellent driving feeling, and it is preferable to perform analog stepped control without restriction.

The degree of the acceleration/deceleration request (the driver's expectation) also corresponds to the degree of driver's driving operation contribution, and it is generally considered that the smaller the degree of driving operation contribution, the smaller the degree of acceleration/deceleration request. For example, it is considered that the unmanned automatic driving mode and the manned automatic driving mode in which the steering angle Φ is automatically controlled have a lower degree of demand for acceleration and deceleration than the cruise driving mode in which the steering angle Φ is operated by the driver, and from this point of view, it is also preferable to make the control region of the engine 12 narrower in the unmanned automatic driving mode and the manned automatic driving mode than in the cruise driving mode to improve the fuel economy.

As described above, the electronic control unit 50 of the vehicle drive apparatus 10 according to the present embodiment includes the up-down-slope AI control unit 66 that controls the automatic transmission 16 so as to maintain the engine rotation speed Ne higher during the traveling on a sloping road than during the traveling on a flat road, and thus can obtain excellent drivability during the traveling on a sloping road, while the increase width of the engine rotation speed Ne during the up-down-slope AI control is limited during the second travel mode (the unmanned, manned, automated travel mode, and cruise travel mode) compared to the first travel mode (the driving operation travel mode), and therefore, fuel economy is improved. In the second travel mode, since the driver does not perform acceleration/deceleration operation, the driver's request for drivability is limited, and there is a low possibility that the driver will be confused even if drivability is slightly deteriorated by limiting the increase width of the engine rotation speed Ne. In particular, in an automatic driving mode in which acceleration and deceleration are automatically performed by setting a target driving state based on road information, it is considered that it is desirable for the occupant to prioritize comfortable ride comfort and fuel economy over drivability.

Further, the following travel mode (cruise travel mode) and the unmanned or manned autonomous travel mode are provided as the second travel mode, and the extent of increase in the engine rotation speed Ne in the up-down slope AI control is made smaller in the autonomous travel mode than in the following travel mode, so that the drivability in the following travel mode can be ensured, and the extent of increase in the engine rotation speed Ne in the autonomous travel mode can be made smaller, thereby further improving the fuel economy. That is, since the follow-up running mode is a mode of running following the preceding vehicle, it is considered that the degree of acceleration and deceleration required by the driver is higher than in the automatic running mode, and the drivability during the slope running is ensured by increasing the engine rotation speed Ne to a greater extent than in the automatic running mode.

Further, the second travel mode includes an automatic steering travel mode (unmanned or manned automatic drive travel mode) and a manual steering travel mode (cruise travel mode), and the range of increase in the engine rotation speed Ne during the up-down slope AI control is made smaller in the automatic steering travel mode than in the manual steering travel mode, so that the drivability in the manual steering travel mode can be ensured, and the fuel economy can be further improved by making the range of increase in the engine rotation speed Ne small in the automatic steering travel mode. That is, in the manual steering travel mode, since the driver operates the steering angle Φ, the degree of contribution of the driver's driving operation is large, and it is considered that the degree of the driver's request for drivability is higher than in the automatic steering travel mode, the range of increase in the engine rotation speed Ne is made larger than in the automatic steering travel mode, and drivability during traveling on a sloping road is ensured.

In the present embodiment, the simulated stepped control unit 68 is provided that controls the electrical differential unit 14 so that a plurality of simulated gear stages, in which the gear ratio γ 2 of the engine rotation speed Ne with respect to the output rotation speed Nout is different, are established, and the engine rotation speed Ne is changed during acceleration/deceleration associated with the gear shift of the simulated gear stages, so that the same driving feeling (drivability, engine noise, etc.) as that of the stepped transmission can be obtained, whereas in the second travel mode (unmanned, manned automatic drive travel mode, and cruise travel mode), the control range of the engine rotation speed Ne during the simulated stepped control is limited as compared to the first travel mode (drive operation travel mode), and therefore, the fuel economy is improved. In the second travel mode, since the driver does not perform the acceleration/deceleration operation, the driver has a limited request for the driving feeling including the drivability, and there is a low possibility that the driver will feel discomfort even if the driving feeling is slightly deteriorated due to the control region in which the engine rotation speed Ne is limited. In particular, in an automatic driving mode in which a target driving state is set based on road information and acceleration and deceleration are automatically performed, it is considered that it is appropriate for the occupant to prioritize comfortable ride comfort and fuel economy over driving feeling.

Further, the following travel mode (cruise travel mode) and the unmanned or manned automated travel mode are provided as the second travel mode, and the control region of the engine rotation speed Ne in the simulated stepped control is made narrower in the automated travel mode than in the following travel mode, so that the driving feeling in the following travel mode can be ensured, and the fuel economy can be further improved by making the control region of the engine rotation speed Ne narrower in the automated travel mode. That is, since the follow-up running mode is a mode of running following the preceding vehicle, it is considered that the driver's request for acceleration/deceleration is higher than in the automatic running mode, and by making the control range of the engine rotation speed Ne larger than in the automatic running mode, excellent driving feeling including drivability can be obtained.

Further, the second travel mode includes an automatic steering travel mode (unmanned or manned automatic drive travel mode) and a manual steering travel mode (cruise travel mode), and in the automatic steering travel mode, the control range in which the engine rotation speed Ne is simulated in the stepped control is made narrower than in the manual steering travel mode, so that the driving feeling in the manual steering travel mode can be ensured, and the fuel economy can be further improved by making the control range of the engine rotation speed Ne narrower in the automatic steering travel mode. That is, in the manual steering travel mode, since the steering angle Φ is operated by the driver, the degree of contribution of the driving operation by the driver is large, and it is considered that the degree of the driving performance request by the driver is higher than that in the automatic steering travel mode, and therefore, by making the control region of the engine rotation speed Ne larger than that in the automatic steering travel mode, it is possible to obtain excellent driving feeling including the driving performance.

Further, the up-down slope AI control unit 66 of the above embodiment restricts the up-shift or forcibly the down-shift of the automatic transmission 16 in order to maintain the engine rotation speed Ne higher during the hill road running than during the flat road running, but may control the rotation speed Nmg1 of the first motor generator MG1 to increase the engine rotation speed Ne in the electrical differential unit 14 functioning as an electrical continuously variable transmission. For example, in the motor running mode in which the vehicle runs with the second motor generator MG2 as the power source, the engine speed Ne may be maintained at substantially 0 during the flat road running, and may be increased in preparation for an acceleration request on an uphill road. Although the engine 12 may be started to rotate autonomously, cranking alone may be performed. In this case, the engine rotation speed Ne may be increased to a smaller extent or may be maintained in a rotation stopped state in a second travel mode such as a cruise travel mode or an unmanned or manned autonomous travel mode. The electric differential portion 14 corresponds to an automatic transmission.

In the above embodiment, the vehicular drive apparatus 10 including the electric differential portion 14 and the automatic transmission 16 capable of realizing the four-stage forward speed change has been described, but the present invention is also applicable to, for example, a vehicular drive apparatus 200 shown in fig. 12, and the like, and the present invention is applicable to various vehicular control apparatuses. The vehicle drive device 200 of fig. 12 relates to a hybrid vehicle including an engine 202 and a motor generator MG as power sources and having an automatic transmission 204 capable of realizing a speed change of eight forward speeds. The engine 202 is coupled to a motor shaft 206 of the motor generator MG via a disconnect clutch K0, and the outputs of the engine 202 and the motor generator MG are transmitted from the motor shaft 206 to an input shaft 222 of the automatic transmission 204 via a torque converter 208. The stator (guide impeller) 210 of the torque converter 208 is selectively stopped from rotating by a stator brake Bs.

The automatic transmission 204 includes a first transmission unit 214 mainly including a double-pinion first planetary gear device 212 and a second transmission unit 220 mainly including a single-pinion second planetary gear device 216 and a double-pinion third planetary gear device 218 on a common axial center, and changes the speed of rotation of an input shaft 222 to output the rotation from an output shaft 224, and drives left and right drive wheels to rotate via a final reduction gear device, not shown, or the like. The carriers and the ring gears of the second planetary gear device 216 and the third planetary gear device 218 are formed of a common member, and the pinion gears of the second planetary gear device 216 and the third planetary gear device 218 are formed as Ravigneaux (Ravigneaux) type planetary gear trains serving as the second pinion gear (outer pinion gear) of the third planetary gear device 218. The automatic transmission 204 is provided with four clutches C1 to C4 and two brakes B1 and B2 (hereinafter, simply referred to as "clutches C" and "brakes B" unless otherwise specified) as hydraulic friction engagement devices, and as shown in an engagement operation table of fig. 13, by engaging any two of the clutches C and the brakes B, forward gear stages 1st to 8th of eight forward speeds and reverse gear stages Rev1 and Rev2 of two reverse speeds can be established, and by releasing all the clutches C and the brakes B, N (neutral) in which power transmission is interrupted can be achieved.

In the vehicle driving apparatus 200, the engine output control device 40, the hydraulic control circuit 42, the automatic brake system 44, the automatic steering system 46, the electronic control device 50, and the like are provided, so that the vehicle can travel in the driving operation travel mode, the cruise travel mode, the manned automatic travel mode, and the unmanned automatic travel mode, and the upward/downward AI control unit 66 performs the upward/downward AI control for each travel mode, thereby obtaining the same operational effects as those of the above-described embodiment.

Although the embodiments of the present invention have been described in detail with reference to the drawings, these are merely embodiments, and the present invention can be implemented by various modifications and improvements based on the knowledge of those skilled in the art.

Description of the reference symbols

12. 202: the engine 14: electric differential portion (automatic transmission) 16, 204: the automatic transmission 50: electronic control device (vehicle control device) 66: upward/downward slope AI control unit (slope travel control unit) MG 1: first motor generator (generator) MG 2: second motor generator (motor) Ne: engine speed Φ: steering angle

Claims

1. A vehicle control apparatus relates to a vehicle having an engine (12, 202) and an automatic transmission (14, 16, 204) serving as power sources,

the vehicle control device (50) is capable of realizing a first travel mode in which driving force control and gear shift control of the automatic transmission are performed in accordance with acceleration/deceleration operations of a driver, and a second travel mode in which a target travel state is set without acceleration/deceleration operations and the driving force control and the gear shift control are performed,

the automatic transmission control device is provided with a slope running control unit (66) for controlling the automatic transmission so as to maintain the engine speed higher during the running on at least one of an uphill road and a downhill road than during the running on a flat road,

the slope travel control unit limits a magnitude of increase in the engine speed in the second travel mode compared to that in the first travel mode.

2. A vehicle control apparatus relates to a vehicle having an engine (12, 202) and an automatic transmission (14, 16, 204) serving as power sources,

the vehicle is a hybrid vehicle that includes an electric motor (MG2) as the power source in addition to the engine, and is capable of motor running in which the vehicle runs only by the electric motor with the engine stopped and engine running in which the vehicle runs by using power of the engine,

3. The vehicle control apparatus according to claim 2,

the slope travel control unit starts the engine in the first travel mode, controls the automatic transmission so as to maintain a higher engine speed than in the flat travel mode in the slope travel mode, and stops the engine in the second travel mode.

4. A vehicle control device relates to a hybrid vehicle including an engine (12, 202), a generator (MG1) rotationally driven by the engine, and a traveling electric motor (MG2) for generating power using electric energy obtained by the generator,

the vehicle control device (50) is capable of realizing a first travel mode in which driving force control is performed in accordance with acceleration/deceleration operation by a driver, and a second travel mode in which driving force control is performed by setting a target travel state without acceleration/deceleration operation,

has a slope travel control unit (66) for maintaining the engine speed higher during a slope travel on at least one of an uphill road and a downhill road than during a flat road travel,

5. The vehicle control apparatus according to claim 4,

the hybrid vehicle is a series hybrid vehicle in which the engine is dedicated for power generation.

6. The vehicle control apparatus according to claim 4 or 5,

the slope travel control unit maintains the engine speed higher during uphill than during flat travel, and reduces the generated power by the generator during uphill in the second travel mode to be lower than during uphill in the first travel mode.

7. The vehicle control apparatus according to claim 4 or 5,

the slope travel control unit starts the engine and maintains a higher engine speed during the slope travel than during the flat travel in the first travel mode, and stops the engine in the second travel mode.

8. The vehicle control apparatus according to any one of claims 1 to 5,

as the second running mode, there is provided a follow-up running mode in which a target driving force with which follow-up running can be performed with respect to a preceding vehicle is calculated and the target driving force is made to run as the target running state.

9. The vehicle control apparatus according to any one of claims 1 to 5,

an automatic driving mode is provided as the second running mode, and the automatic driving mode is a mode in which the target running state is set based on road information and acceleration and deceleration are automatically performed.

10. The vehicle control apparatus according to any one of claims 1 to 5,

a plurality of running modes different in the degree of the driver's request for acceleration/deceleration are provided as the second running mode,

in the second running mode in which the degree of the requirement for acceleration/deceleration is small, the slope running control unit decreases the increase width of the engine speed to be smaller than that in the second running mode in which the degree of the requirement for acceleration/deceleration is large.

11. The vehicle control apparatus according to any one of claims 1 to 5,

as the second travel pattern, there are provided a follow-up travel pattern in which a target drive force with which follow-up travel can be performed with respect to a preceding vehicle is calculated and travel is performed with the target drive force as the target travel state, and an automatic drive travel pattern in which the target travel state is set based on road information and acceleration and deceleration is automatically performed,

in the automatic driving mode, the slope travel control unit decreases the increase in the engine speed to a smaller extent than in the follow-up travel mode.

12. The vehicle control apparatus according to any one of claims 1 to 5,

as the second travel mode, there are provided an automatic steering travel mode that is a mode of traveling with a steering angle automatically controlled based on road information, and a manual steering travel mode that is a mode in which a driver operates the steering angle,

in the automatic steering drive mode, the slope travel control unit increases the engine speed to a smaller extent than in the manual steering drive mode.